Method of making diaphragms



June 17; 1947. E. COFFEY METHOD OF MAKING DIAPHRAGIS Original Filed June 15, 1944 2 Sheets-Sheet 1 FIG. I.

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nwuvroa IRVEN E. COFFEY June 17, 1947. l. E. COFFEY METHOD OF MAKING DIAPHRAGMS 2 Sheets-Shet 2 Original Filed June 15, 1944 FIG.5.

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INVENTOR; IRVEN'ECOFFEY' Patented June 17, 1947 I Irven E. Coffey, Normandy, Mo., assignor to Carter Carburetor Corporation, St. Louis, Mo., 2. corporationof Delaware Original application June 15, 1944, Serial No.

540,464. Divided and this applicatlon'September 13, 1945, Serial No. 616,137

This invention relates to diaphragms and particularly to diaphragms for fuel pumps and the.

like and is a division of my application Serial No. 540,464,!iled June '15, 1944. I i

An important use of the diaphragm is in connection with the fuel pump such as disclosed in my 'copending application, Serial No. 536,162, g}

filed May 18, 1944. Diaphragms of this character are'made on a cloth base and are'coated or im'-.-

pregnated with a material such as synthetic Claims. (or. 28:14)

rubb'enwhich is resistantto the action of the gasoline or other liquid which is to be'pumped. One of -the inherent characteristics of the-diaphragm is that it must be flexible enough to permit distortion into a substantially frustoconical shape by the diaphragm operating means terial'after the application of. the synthetic rubwhile the edges of the diaphragm are rigidly her, the top layer of rubber being removed for held. Since the synthetic rubber with which the inspection o the fa ic. v e t diaphragm is coated has comparatively little F g. 8 shows the methodof app y the sy tensile strength,'the cords of the fabric forming. thetic r er to t e r I the base of the diaphragm mu t, b relied o t The reference numeral l indicates the main supply the'necessary tensile strength. The servbody member f the uel pump having a flan 1 ice required of diaphragms in fuel pumps for by means of which it is adapted to be mounted automotive engines is severe, as they have to 011 a e g ne, 01 machine, to which it is to be operate at high speed under considerable tenattached Uperetins v r 3; or y yi l in ly-l sion for thousands of hours duringthe life of held i the position shown by the Spring is the car. For this reason, considerable diaphragm connectedto the diaphragm's 5 y a e trouble has been experienced by fuel pump man- Way connection which has no bear heionthe ufacturers in spite of h expedie'nts as 1- present invention and is not shown herein. .The tiple thickness and multiple layer diaphragms. full structural details of the pu a eo i Up to the time of this invention, it has been immy above mentioned cope g app a he P ss to Obta n a satisfactory dlaph1&gm .parflexible diaphragm 6 is mounted between flanges. ticularly of the single layer, rubber coated type 1 a d"! a m y b p i d. w th p r rat ns 9 Y which is most desirable for fuel pump use. 'l f the'flange bolts rivets; The p p It is an object. of my invention to produce is provided with an inlet l0 and an outlet II, toi new and improved diaphragm of the syntheti gether with suitable valves for controlling the rubber coated type which will be capable of i let and-outlet. The cent a part of the dialasting the full life of the automobile when used pliragm'fi is rigidly clamped between the wash-a in automotive fue1 pump s r i e; v e-rs l2 and I3, which are especiallyshaped as It is a further object of my invention to pro- 40 herein and as'iclaimed in my h n ing duce a. new and improved diaphragm in which DD t Operating D l e1d---i f strains applied in distorting the diaphragm will place be the a rs l2 and 15 serves to be evenly resisted by the threads of the cloth in V maintain a constant i ar pr re or the 1- both directions. pump. 0 o

It is a further object of my'invention to pro- '45 In e pe a of a p p, it is ous that duce new and improved diaphragm material the ph a 'mhst be shi ted from the position which can easily be made in large quantities-;-. li' t0 he flat position correrj while maintainingthe high standards of duraspending to Fig. 2 and. finally, to a po'sitionrcor; bility and strength. I respondingtdth dotted lines I6 shown in Fig. 1.

It is a further object of my. invention to pro- This reqiiires the diaphragm to be not only flexduce a-new and improved method of making diaible, but resilient, and since the reciprocating phragms of the above described character. action of .the diaphragm mustbe very rapid on; a

The invention will be better understood upon der certain conditions, heavy strains are imposed reference to the following specification and acdue to the inertia of the liquid which must be companying drawings: accelerated and decelerated'in the 2 Fig. 1 shows a diaphragm, according to my invention, mounted in a fuel pump of the type shown in my copending application Serial No. 7

536,162, filed May 18, 1944.' Fig. 2 shows a sectional elevation of a diaphragm assembly separate from the pump.

Fig. 3 is a plan view of a. single diaphragm as shown in Figs. 1 and 2.

Fig. 4 is a plan view showing theweave of the fabric upon which my diaphragm is based.

Fig. 5 shows a longitudinal. sectional view of p the fabric shownin Fig. 4. r Fig. 6 shows a transverse sectional view of the.v

fabric.

Fig. '7 is a sectional plan view showing the ma u p/a'nd down which serves as the base on which my diaphragm is formed. The warp i1 is more widely spaced than the weft, l8, and the tension of the weft is initially greater than that of the warp, so that the additional tens-ion or stretching applied dur- As stated above,

ing the rolling operation will equalize the spacing and also the tension. The cloth is made of the best yarn obtainable which may be cotton, rayon, or nylon.

The fabric I9 is impregnated by passing between rolls 2B and 2| which are supplied with Buna-N or other synthetic rubber in a plastic anduncured condition. As indicated at .22, the rubber builds up a gob on each side of the cloth at the entering side of the rolls. This gob .is continuously supplied by means of the uncured Buna-N 'rubber strips '23 and 24 which are fed into the gob as required. Suitable spacing in tension of the rolls is provided by a mounting which is diagrammaticallyindicated at 25' and 26 with .adjustablezspring means 21 for controlling the pressure and spacing. The pressure is sufflcient to press the uncured rubber into the interstices between the threads, so that they j oin in the middle as indicated at 28'.

During the rolling operation, theresistance of the gobs 2-2 to passing through the rollers sets up a very substantial tension tending to stretch the warp away from the rollers. By feeding the cloth in the direction of the warp, I, am thus able to equalize both the :weave and the tension as it passes through the rolls. It will. be understood that the'impregnated diaphragm material 29 is treated to cure the rubber after it leaves the rolls 20 and 2|. However, the details of this operation are well known in the art and need not be further shown or described.

While the material produced by the herein de-- scribed method has been described chiefly in connection with its use for pump diaphragms, it will be obvious that it has many uses, not only for diaphragms of all kinds, but wherever a heavy and strong rubber impregnated cloth is desired.

I claim:

1. The method of making diaphragms which comprises weaving a cloth with unequal tension on the warp'and weft, impregnating and coating the cloth with a plastic material by passing the cloth between rolls to which the plastic material is supplied, and adjusting the position of the cloth so that it passes through the rolls in the direction 'of the looser threads so as to equalize the tension of the warp and weft.

-2'. The method of making diaphragms which comprises weaving a cloth with the threadsin one direction at greater tension than the threads While I prefer to use the above described method in the performance of my invention, it sometimes happens that the amount of-diaphragm material to be made does not justify setting up a loom withzthe desired spacing and tension of the weftwith respect to the warp. In such cases, the weft is usually made with substantially the same initial spacing in the cloth as the warp, but with less tension. When only this type of fabric is avail-able, I prefer to cut the fabric into squares,

turning each square sidewise, and sewing it to the I side of the adjacent square so asto form a strip of cloth which may be the same width as the cloth which originally came from the loomor any other desired width. This strip of cloth is then placed on a roller and fed into the impregnating.

rolls 20 and 2|. so as to increase the tension on the weft, 1- which, in that. case, passes longitudinally through the rolls. Thismethod results in an impregnated and coated fabric in-which the tension 7 on the warp and weft is equalized, al

spacing may not be identical. e

In this connection, it may be noted that. it is the length of the rolls 2!) and'2l which controls the width of the cloth which may be impregnated, and, where small quantities of material are required, the alternative method above described may be used to advantage by cutting the original though the cloth into short sections which are sewn together 'edgewise to form a narrow strip with the weft running longitudinally.

extending crosswise thereof, applying plastic coating material to the surface of the cloth, and

passing-the cloth between pressure elements in Q the direction. of said looser threads whereby the plastic material is pressed into the interstices. of.

the cloth and, the cloth 7 is simultaneously stretched ,so' as to substantially equalize the tension of the crossed threads. r

crossed threads.

4. The method of makinga pump diaphragmwhich comprises weaving a clothwith threads of equal size and strength but unequal tension with j respect to 'the warp and weft, applying a mass of uncured, synthetic rubber to-each surface of: the cloth, and rolling the synthetic material into. the interstices of the cloth in the-direction of the looser threads, the roller pressure being adjusted. so as to stretch the looser threads justsufliciently to equalize the tension of the warp and weft. V

5. The method of making aflexible pump dia-- phragm which. comprises weaving a cloth with; threadsof substantially equal strength and size but at. unequal tension and unequally spaced the threads at greater-tension being -closerjto- Y gether than the crossed-threads, applying a mass.

of uncured, synthetic rubber to each surface of the'cloth, passing thesynthetic rubber and cloth between pressure elements in the direction of; the looser threads, and adjusting the pressure of the threads in both directions.

REFERENCES. CITED,

The following references are oirecordin thei file of this patent: V

STATES PATENTS. f

Date 2 

